Box tool



June 14, 1949. r K. FELLROTH BOX TOOL Filed July so, 1945 2 sneaks-sheet 1 Patented June 14, 1949 Kart Fellroth Minneapolis; 'Minnt Application Jnly.30;-1945,' Serial No. 607,832 i claim. (01. 82 35)" My invention relates to improvementsin .box' a= flat vertically disposed relatively narrow 'l'eQ- tools and; more particularly-to athree-roll'er tangular block of metal. In the center ofthe pressuresystem for a'box tool. head 6 is an annular work opening i that extends-w It is well known that in the ordinarytworoller completely through said head from theiront to box'tool, the cutting bit isa part of the pressure" the'backthereof. The lowercorners of the head system for holding stock while itis being turned". t; that extend from the front to the backthereof The principal object of my invention is tQiDIO- are rounded at-8 and the overlying portions of videa three-roller pressure system and eliminate the top'of'thehead t are-outwardly rand downthe use of the cutting bit'as a part of this system. wardly'inclinedto afford bearing surfacesfl', for a By eliminating the cutting bit from the pressure" 10 purpose which will presently appear.

system; said bit may be adjusted without up- Twochip escape passageways liland llzin'ithesetting theadjustment'of the rollers. Thisthree face of the head'G extend to the back ofsaid 1. roller pressure system gives rigid support to stock head. These two passageways ill and I I l lead. being turned and prevents the stock"from-"turnfrom the work opening-1, on opposite sidesthere ing into and out of concentricity'. of and extend outwardly and doWnWardIy the A further object of this inventionis to mount former on the right hand sideof the head litand the cutting'bit parallelto' the cut'b'eingmade the latter onthe left-hand side thereof. The: therebyand thus eliminate the' di'fiicultyofcorpassageways Ill and ii also afford sight open u rectly: grinding th'e cutting .bit, as is in the case of ings into the work opening I the' ordinarybox-tool in" which the cutting. bit On the 'back of the head 6 and integral theree is at'an angle to the cut;.and requiresa highly with is a rear extension i2 comprising laterally Skilled; well p en d a s n to' rimi spaced sidemembers i3 and -a back member l4. same. The manner in which my. cutting. bit is This rear extension 12 forms a large rectangulanf mounted, relative to the out, only requiresthe vertical opening it at the back of the headfi: rindin h with an ordinary-- chin breaker The head 6 extends materially above and below with proper rakes an'dclearances. the rear extension l2 and the outer'faces ofthe By im nat he u t nsh t sa par f the side members were flush with the sides-of thepressure system, anexceedingl-y heavy cut-may head .6.

be taken with true concentricityof-the cut.-- The A hollow round shank it; for mounting'thethree-rollelpressure Y 'P m S- e rol e s-'30 box-tool A on a lathe turret or tailstock; has to be adjusted onto the stockto put ahigh burnish one oiitsend portions tightly fitted ina hole thereon. This three-rollersystemalso eliminates in theb'ack member M with said shank axially th ne s y r r e s eh v r on x t ls aligned with the axis of the work o enin i. An" because thethreerollersexert pressure-on the annular flange l1, integral with theshank l6,- stOc and-the efor ,-w e p p y= di i bears. against. the back member M andis dcnot leave-tool-markson thecut surfaceotthe tachably secured thereto by three cap screws stock when drawing the tool -back f rom itswork. i la Theseand other objects of the invention-will A' r latively long cutting or tool bit I9 is be-apparent from the following description reh nted-1m seat .20 i a, bo s 2| on the head erence being had tothedrawings: 6. This boss 2! extends forwardly of thefacv Ot e aboveend, generally -y" of thehead 6 and outwardly from 'the'right-hand tion consists ofithe novel devices andconrbinaside-.o i id h T tool it l9'is rectangular tion of'devices hereinafterdescribed and defined in .crosesection d has a clos working fit'with in the claim. H thetseatlt' on all'sides thereof; This seat 20 is In th a mp ny d aw n s;-w l u in the form ofa longpassageway which extends the invention; like-characters indicate like parts horizontally and transversely'of the Work open''' th o th several v w m s! .and. opens through the wall of said-work- Referring to thedrawings opening. The cutting edge of the tool'bit His Fig. 1 is a front elevation of the improved box p-t upper, e thereof and said; upper ide tool; isomer radial line extending from the axis ofth'e i 2 s a bottom pl n i w f th Same; worho enin -i. In other words, the tool bit I9 Fig. 3 is-a left-hand side elevation of the box is parallel ti t out ma e thereby.

o s Shown in i w h so e p ts broken To adjustlthe tool bit l9towerd its WO1k,I

y Part5 sectioned; provide a thumb-screw 22' having .thread'eden= Fig- 4'is'a V ew p t y 'p bu p i c y gagement'with' the boss M. This thumb-screw in horizontal section takenhorizontally through z'z'j s n axial n' m t t t t g -w the box tool at differentelevationszand impinges the outer end thereof. The toolbit 19" Fi is a f a a y d a view r ly in is positively held? Where adjusted by two set side. elevation and partly'inv'ertical sectionitaken r 23 and as having threaded engagement on the-line 5 '--5 ofFi'gJlL with th'elboss '21. These set screws 23and'2'4 ex The-numeral 6" indicatesth'e head oi rri'yiiimtend atfrightengles toeach' other, withthe tor provedbox'tool A; which; as'sh'own, is formedcf mer implngingthe 'outer side of thetool'b'itifl and the latter impinging the under side thereof.

The thumb-screw 22 is positively held where adjusted by a set-screw 25 having threaded engagement with'the boss 2! on its under side. A brass plug 26 is interposed between the thumbscrew 22 and the set-screw 25 to prevent said setscrew from mutilating the thread of the thumb screw 22.

A vertical sight opening 27 extends through the boss 2| to expose the contacting end portions of the tool bit I9 and the thumb-screw 22. In actual construction, the thumb-screw 22 will have a micrometer adjustment. It may be here stated that the tool bit [9 will, of course, be ground with the customary chip breaker on its upper edge and with the proper rakes and clearances.

My invention includes a three-roller pressure system; two upper rollers and a lower roller 28. Each roller 28 is mounted on a carrier 29, in the form of an elongated block, slidably mounted in a, channel guide 30 in the face of the head 6. The carriers 29 are bifurcated at their inner end portions to afford pairs of bearing lugs 3! be tween which the rollers 28 rotate. Said rollers 28 are journaled on studs 32 that extend through aligned holes in the pairs of bearing lugs 3!. Long set-screws 33 extend longitudinally into the carrier 29 from the outer ends thereof, have threaded engagement therewith, impinge the studs 32 and rigidly hold the same in the bearing lu s 3|.

%3ne side of each channel guide 3b is perpendicular to the face of the head 6 and the other side thereof is inwardly and outwardly inclined. The carriers 29 slidably rest on the bottoms of the channel guides 30 and their sides have a close working fit with the sides of said guides. In the perpendicular side of each carrier 29 is a longitudinal groove 34. Each carrier 25 is positively held where adjusted in its channel guide 30 by a set-screw having threaded engagement with the head 6, extends into the respective groove 3t. and impinges said carrier. The purpose of the grooves 34 is to prevent the set-screws 35 from multilating the carriers 39 Where they would have sliding contact with the respective sides of the channel guides 30.

The two upper channel guides 30 are in upwardly diverging relation and extend on angles of about thirty-two degrees from a vertical plane passing through the axis of the working opening 1. When the rollers 28 are adjusted to their innermost positions, they are close to each other and to the axis of said work opening. This relative arrangement of the two upper rollers 23 makes it possible for them to hold stock of a relatively small diameter. The lower guide channel 30 is in a vertical plane passing through the axis of the work opening I and midway between the two upper rollers 28.

The rollers 28 and the tool bit is ar i t same vertical plane and the outer faces of said rollers are very close to the cutting point on said bit which is on its upper outer corner, see Fig. 3. Due to the close proximity of the rollers 28 to the tool bit y a very slight cut is made in the stock being turned before said stock is fed between said rollers. As soon as the stock enters between the rollers 28, the operator first adjusts justed into engagement with the stock and rotated thereby. Obviously, the three-point circumferential contact of the rollers 28 with the 50 on each carrier,

stock positively holds said stock against movement into and out of concentricity.

Each carrier 29 is moved endwise in its channel guide 30 by a long adjusting screw 36, having threaded engagement with a nut-acting lug 3? on the bottom of said carrier. The lugs 37 work in deep grooves 38 into the bottoms of the channel guides 30. The outer end portions of the adjusting screws 36 are smooth and turnably mounted in bushings 39 in bearing plates 58. These bearing plates 40 are secured to the head 6 by pairs of cap-screws 4| and the two upper bearing plates 40 are in the surfaces 9. On the inner end of each adjusting screw 35 is a pilot gaged by the respective bushing 39. The adjusting screws 36 are held against endwise mcvement by the head 6 at the iner end of the grooves 38 and the bushings 39. The bushings are positively held where endwise adjusted in the bearing plates 40 by set-screw 5, see Fig. 5. A. brass plug is interposed between the set-screws 44 and the bushings 39 and thereby prevents mutilation of the bushing 39 which would interfere with their free sliding movement in the bearing plates 40.

In the end portion of each carrier 29 is a lubricating element 46.

The drawings illustrate a commercial form of the invention, but it will be understood that the herein disclosed.

What I claim is: In a box tool, a head having in its face a work opening, three radially disposed channel guides in the face of the head and having open ends, two of the channel guides being in close proximmounted in each channel guide, thre ro lers journaled, one on the inner end of each carrier for holding a piece of stock therebetween, at air-- cumferentially spaced points, a nut-acting lug an adjusting screw having threaded engagement with said lug, a displaceable bearing plate closing the outer end of each channel guide, an adjustable bushing each bearing plate in which the adjusting screw is turnably mounted, said adjusting screws being held by the head and the bushings against end- KARL FELLROTH.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 56,840 Wolfenden July 31, 1866 1,368,252 Flanders Feb. 15, 1921 FOREIGN PATENTS Number Country Date 364,950 France Aug. 31, 1906 545,143 Great Britain May 12, 1942 661,771 Germany June 27, 1938 

